diff --git a/core/lib/Drupal/Core/Config/Schema/Sequence.php b/core/lib/Drupal/Core/Config/Schema/Sequence.php
index a399583..43d3134 100644
--- a/core/lib/Drupal/Core/Config/Schema/Sequence.php
+++ b/core/lib/Drupal/Core/Config/Schema/Sequence.php
@@ -8,6 +8,7 @@
 namespace Drupal\Core\Config\Schema;
 
 use Drupal\Core\TypedData\ListInterface;
+use Drupal\Core\TypedData\TypedDataInterface;
 
 /**
  * Defines a configuration element of type Sequence.
@@ -49,4 +50,26 @@ public function onChange($delta) {
       $this->parent->onChange($this->name);
     }
   }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function first() {
+    return $this->get(0);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function get($index) {
+    return $this->offsetGet($index);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function set($index, $value) {
+    $this->offsetSet($index, $value);
+  }
+
 }
diff --git a/core/modules/link/lib/Drupal/link/Tests/LinkItemTest.php b/core/modules/link/lib/Drupal/link/Tests/LinkItemTest.php
index e8af116..ccc9a91 100644
--- a/core/modules/link/lib/Drupal/link/Tests/LinkItemTest.php
+++ b/core/modules/link/lib/Drupal/link/Tests/LinkItemTest.php
@@ -58,7 +58,7 @@ public function testLinkItem() {
     $class = $this->randomName();
     $entity->field_test->url = $url;
     $entity->field_test->title = $title;
-    $entity->field_test->get('attributes')->set('class', $class);
+    $entity->field_test->first()->get('attributes')->set('class', $class);
     $entity->name->value = $this->randomName();
     $entity->save();
 
@@ -79,7 +79,7 @@ public function testLinkItem() {
     $new_class = $this->randomName();
     $entity->field_test->url = $new_url;
     $entity->field_test->title = $new_title;
-    $entity->field_test->get('attributes')->set('class', $new_class);
+    $entity->field_test->first()->get('attributes')->set('class', $new_class);
     $this->assertEqual($entity->field_test->url, $new_url);
     $this->assertEqual($entity->field_test->title, $new_title);
     $this->assertEqual($entity->field_test->attributes['class'], $new_class);
diff --git a/core/modules/rest/lib/Drupal/rest/Tests/NodeTest.php b/core/modules/rest/lib/Drupal/rest/Tests/NodeTest.php
index 76773df..86df206 100644
--- a/core/modules/rest/lib/Drupal/rest/Tests/NodeTest.php
+++ b/core/modules/rest/lib/Drupal/rest/Tests/NodeTest.php
@@ -81,7 +81,7 @@ public function testNodes() {
 
     // Reload the node from the DB and check if the title was correctly updated.
     $updated_node = entity_load('node', $node->id(), TRUE);
-    $this->assertEqual($updated_node->get('title')->get('value')->getValue(), $new_title);
+    $this->assertEqual($updated_node->getTitle(), $new_title);
     // Make sure that the UUID of the node has not changed.
     $this->assertEqual($node->get('uuid')->getValue(), $updated_node->get('uuid')->getValue(), 'UUID was not changed.');
   }